diff --git a/Logic/Propositional_logic/Boolean_algebra.md b/Logic/Propositional_logic/Boolean_algebra.md index df685fd..1dea69e 100644 --- a/Logic/Propositional_logic/Boolean_algebra.md +++ b/Logic/Propositional_logic/Boolean_algebra.md @@ -45,13 +45,37 @@ $$ x \lor (y \land z) = (x \lor y) \land (x \lor z) $$ -Compare for instance how this applies in the case of [multiplication](/Mathematics/Prealgebra/Distributivity.md): +Compare how the [Distributive Law applies in the case of algebra based on arithmetic](/Mathematics/Prealgebra/Distributivity.md): $$ a \cdot (b + c) = a \cdot b + a \cdot c $$ -In addition we have [DeMorgan's Laws](/Logic/Laws_and_theorems.md/DeMorgan's_Laws.md) which express the relationship that obtains between the negations of conjunctive and disjunctive expressions +### Double Negation Elimination + +$$ + \lnot \lnot x = x +$$ + +### Idempotent Law + +$$ + x \land x = x +$$ + +> Combining a quantity with itself either by logical addition or logical multiplication will result in a logical sum or product that is the equivalent of the quantity + +### DeMorgan's Laws + +In addition we have [DeMorgan's Laws](/Logic/Laws_and_theorems.md/DeMorgan's_Laws.md) which express the relationship that obtains between the negations of conjunctive and disjunctive expressions: + +$$ +\lnot(x \land y) = \lnot x \lor \lnot y +$$ + +$$ + \lnot (x \lor y) = \lnot x \land \lnot y +$$ ## Applying the laws to simplify complex Boolean expressions @@ -110,11 +134,4 @@ Whenever we simplify an algebraic expression the value of the resulting expressi ### Significance for computer architecture -The fact that we can take a complex Boolean function and reduce it to a simpler formulation has great significance for the development of computer architectures, specifically [logic gates](/Electronics_and_Hardware/Digital_circuits/Logic_gates.md). It would be rather resource intensive and inefficient to create a gate that is representative of the complex function. Whereas the simplified version only requires a single [OR gate](/Electronics_and_Hardware/Digital_circuits/Logic_gates.md#or-gate) - -// TO DO: - -- Use truth tables to show equivalence -- Explicitly add implicit laws -- Link to deductive rules -- Link to digital circuits and NANDs as universal gates +The fact that we can take a complex Boolean function and reduce it to a simpler formulation has great significance for the development of computer architectures, specifically [logic gates](/Electronics_and_Hardware/Digital_circuits/Logic_gates.md). It would be rather resource intensive and inefficient to create a gate that is representative of the complex function. Whereas the simplified version only requires a single [OR gate](/Electronics_and_Hardware/Digital_circuits/Logic_gates.md#or-gate).